Chemical mechanical process (CMP) has become a widely used technique for polishing certain work pieces. Particularly, the computer manufacturing industry has begun to rely heavily on CMP processes for polishing wafers of ceramics, silicon, glass, quartz, metals, and mixtures thereof for use in semiconductor fabrication. Such polishing processes generally entail applying the wafer against a rotating pad made from a durable organic substance such as polyurethane. To the pad is added a chemical slurry containing a chemical solution capable of breaking down the wafer substance and an amount of abrasive particles which act to physically erode the wafer surface. The slurry is continually added to the spinning CMP pad, and the dual chemical and mechanical forces exerted on the wafer cause it to be polished in a desired manner.
To effectively work over a period of time, a CMP pad needs to be kept in good condition so that distribution of abrasive particles is optimized for each polishing. One method of reducing “glazing” or accumulation of debris on the CMP pad is dressing or conditioning the pad. Dressing refers to attempts made to revive the top of the pad by “combing” or “cutting” it with various devices. Many types of devices and processes have been used for this purpose. Some CMP pad dressers cause the CMP pads to prematurely wear out.